import time
from machine import ADC, Pin
import math

sensor = ADC(Pin(26))
button = Pin(22, Pin.IN, Pin.PULL_UP)
led = Pin(27, Pin.OUT)

def read():
    analog = sensor.read_u16()
    Beta = 3950
    celsius = 1 / (math.log(1 / (65535 / analog - 1)) / Beta + 1.0 / 298.15) - 273.15;
    return celsius

while True:
    led.toggle()
    temp = read()
    if button.value(1):
        print("temperature: {:.1f} c".format(temp)) 
    else:
        print("")
    time.sleep(1)

    

read()